The variety of leisure and physical activity one engages in -- and not its intensity in terms of calories expended - may reduce dementia risk in older people, according to researchers at Johns Hopkins.

General physical activity is already known to enhance cardiovascular health and help maintain independence and quality of life in older people, but the results of this study - which establish a statistical association, and not a direct cause and effect, between variety of exercise and reduced dementia risk -- suggest that participating in a number of different activities may be as or more important than frequency, duration, and intensity of physical activity with respect to dementia risk, according to the report.